GRADES = [4,5,6,7,8,9,10]
GRADES_DESCRIPTIONS = ["fail", "tolerable", "decent", "satisfactory", "good", "excellent", "outstanding"]
subject_list = []
course_amount_list = []
grade_average_list = []


def loppu(aineka, kurssika, maxaine, max, minaine, min):
    print("Average of all subjects is {:.1f} ({:s})".format(aineka, describe_grade_average(aineka)))
    print("Average of all courses is {:.1f} ({:s})".format(kurssika, describe_grade_average(kurssika)))
    print("The strongest subject is {:s} with average {:.1f} ({:s})".format(maxaine, max, describe_grade_average((max))))
    print("The weakest subject is {:s} with average {:.1f} ({:s})".format(minaine, min, describe_grade_average(min)))


def input_course_grades_and_calculate_average(subject, number_of_courses):
    yht = 0
    for i in range(1, number_of_courses + 1):
        arvosana = int(input("Grade received for the course {:s} {:d}\n".format(subject, i)))
        yht += arvosana

    return yht / number_of_courses




def calculate_averages(grade_average_list, course_amount_list):
    x = 0
    for u in grade_average_list:
        x += u
    aineka = x/len(grade_average_list)
    x = 0
    y = 0
    for o in range(len(course_amount_list)):
        x += course_amount_list[o]*grade_average_list[o]
        y += course_amount_list[o]

    kurssika = x/y
    return aineka, kurssika


def describe_grade_average(grade_average):
    n = int(round(grade_average, 0) - 4)
    kuvaus = GRADES_DESCRIPTIONS[n]
    return kuvaus


def find_strongest_and_weakest_subject(subject_list, grade_average_list):
    maxx = max(grade_average_list)
    minn = min(grade_average_list)
    maxaine = subject_list[grade_average_list.index(maxx)]
    minaine = subject_list[grade_average_list.index(minn)]
    return maxx, minn, maxaine, minaine


def main():
    print("The program calculates averages and analyzes your school performance.")
    subject = input("Enter the next subject:\n")
    subject_list.append(subject)
    while subject != "":
        number_of_courses = int(input("How many courses of {:s} did you attend?\n".format(subject)))
        course_amount_list.append(number_of_courses)
        ka = input_course_grades_and_calculate_average(subject, number_of_courses)
        grade_average_list.append(ka)
        subject = input("Enter the next subject:\n")
        subject_list.append(subject)


    aineka, kurssika = calculate_averages(grade_average_list, course_amount_list)
    maxx, minn, maxaine, minaine = find_strongest_and_weakest_subject(subject_list, grade_average_list)
    loppu(aineka, kurssika, maxaine, maxx, minaine, minn)

main()